1. Field of the Invention
The present invention generally relates to a wireless communication system and, in particular, to a retractable antenna for an electronic communication card that allows wireless communication.
2. Description of Related Art
Computers are often connected to various communication systems to communicate, exchange data, and transmit various types of information. In particular, computers are often linked by communication systems or networks such as Local Area Networks (LANs), Wide Area Networks (WANs), Internet, Ethernet and conventional telephone networks. These communication systems typically require the computers to be physically attached by wires such as telephone lines or other specialized wiring. In some locations, however, it is difficult if not impossible to be physically connected to a communication system. Additionally, these communication systems generally cannot be used if the user is traveling or moving between locations.
Conventional computers often use electronic communication cards to connect to these communication systems or networks. The communication cards are often in the form of modular cards that can be plugged into a slot or receiving port in the computer. These communication cards can be easily inserted and removed for use with different computers and the cards allow communication with different networks or systems to be established. These communication cards are often constructed according to the Personal Computer Memory Card International Association (PCMCIA) guidelines or standards for purposes of compatibility and wide use. Communication cards that conform to these standards are often referred to as PCMCIA or PC cards.
It is also known to use cellular telephones and other wireless systems to connect computers to various communication systems and networks. Cellular telephone systems are particularly effective in allowing computers to communicate because the computers do not have to be physically connected to telephone lines or other specialized wiring. In contrast, the computers are connected to the communication system by the cellular telephone network. Additionally, cellular telephone systems are very useful in connection with portable computers because the cellular communication circuitry can be miniaturized and provided as a component of the computer.
These known cellular telephone systems and other types of wireless communication networks require the use of antennas. Conventional antennas are typically placed external to the body of the computer because of noise, interference, obstruction and shielding caused by the various components of the computer. Conventional antennas generally do not function correctly if they are obstructed or shielded by the housing or other structures of the computer.
Conventional antennas are generally rigid and protrude a relatively long distance from the body of the computer. These protruding antennas are often large, unwieldy, aesthetically unpleasing and they make the computer difficult to move and transport. In addition, these antennas are often bent, broken, knocked out of alignment or otherwise damaged because they can easily catch or strike objects such as people, walls, doors, etc. Further, these known antennas require a large support structure to secure the antenna to the housing of the computer and this support structure requires a considerable amount of space inside the body of the computer. This space is very valuable, especially in small, portable computers. Additionally, the support structure is often damaged when the antenna is accidentally moved.
The repair and replacement of conventional antennas and the associated support structure is often difficult and costly. In fact, the entire antenna assembly is often removed and replaced instead of attempting to repair a portion of the antenna or support structure. Thus, the repair and replacement of the antenna and/or antenna support structure is expensive and time consuming.
In order to alleviate these problems, conventional antennas are often removed or detached from the computer before it is moved or transported. Additionally, conventional antennas must often be removed before the computer can be inserted into its carrying case. Disadvantageously, this requires additional time and resources to remove and reattach the antenna each time the computer is moved. Additionally, when the antenna is detached from the computer, it is often misplaced, lost or damaged. Further, because the user often does not want to take the time and effort to remove the antenna, the computer is moved with the antenna still attached to the computer and this frequently results in the antenna being damaged or broken.
It is known to use a telescoping antenna in an attempt to minimize these problems. For example, U.S. Pat. No. 5,684,672 issued to Karidis, et al. discloses a laptop computer with an integrated multi-mode antenna. The telescoping antenna is integrated into the cover or display portion of the laptop computer and it outwardly extends from the display portion for use. The telescoping antenna is then retracted into the display portion when it is not in use. A coaxial cable connects the antenna to the base of the computer. In particular, the coaxial cable connects the antenna to a radio frequency (RF) adaptor card inserted into a PCMCIA slot located in the base of the computer. Disadvantageously, the telescoping antenna disclosed in the Karidis patent is large, extends a great distance from the body of the computer, and requires the user to manually extend and retract the antenna.
It is also known to attach an antenna to a drawer that can be extended and retracted from the housing of a computer. U.S. Pat. No. 5,557,288 issued to Kato, et al., discloses a drawer that passes through an opening in the housing of the computer when it is moved between the extended and retracted positions. When wireless communication is desired, the user must open a door to the opening in the housing, extend the drawer through the opening, and rotate and extend the antenna into the desired position. When the wireless communication is finished, the user must rotate and withdraw the antenna into a storage position, retract the drawer into the computer, and close the door to the opening. Disadvantageously, the system disclosed in the Kato patent requires numerous steps by the user before wireless communication can be established, and numerous steps to retract and store the antenna. Further, the device disclosed in the Kato patent requires a large amount of space, which is very valuable in portable or compact computers.
A disadvantage of these known systems is the antenna is always operable and ready for wireless communication. Thus, inadvertent wireless communication may occur, or wireless communication may occur when it is prohibited. Additionally, the antenna may transmit or receive wireless signals while it is stored inside the computer, which may cause interference and disrupt the operation of the computer. Another disadvantage is the antenna system is continually drawing power from the computer. This is especially a problem with portable or smaller-sized computers that have a need for a long-lasting and portable power supply. Because portable computers are often used in environments where access to conventional power supplies are not available, a battery or similar power supply is needed. The electrical storage capability of the battery, however, is generally in direct proportion to its physical size. Thus, in instances where a smaller battery is used, there is a need to conserve the electrical power used by the computer, and any connected peripherals, to lengthen the usable life of the battery.
A need therefore exists for an antenna system for a communication card that eliminates the above-described disadvantages and problems.
One aspect of the present invention is an antenna system for a communication card. The antenna system advantageously provides wireless or radio frequency (RF) communication with other networks or communication systems to allow data and other information to be shared or exchanged. The antenna system includes an antenna attached to a retractable platform that is selectably movable between an extended position and a retracted position. When wireless communication is desired, the retractable platform is located in the extended or use position and the antenna is substantially disposed outside of the body of the communications card. When wireless communication is not desired, the retractable platform and antenna are stored inside the body of the communications card in the retracted or stored position. This stored position protects the retractable platform and antenna from damage. Advantageously, the antenna can be quickly and easily positioned in the extended position for use, and it can be simply and promptly placed in the stored position when wireless communication is not desired.
Another aspect is an antenna system in which wireless communication is unavailable or inoperative when the retractable platform is in the storage position. Wireless communication, however, is available and operable when the retractable platform is in the extended position. Preferably, the antenna system is automatically operable and ready for use in the extended position, and is automatically inoperable in the storage position. That is, the antenna system is automatically turned on or enabled in the extended position, and turned off or not enabled in the storage position. Desirably, this process occurs without any intervention by the user other than to extend or retract the retractable platform.
Yet another aspect of the antenna system is a control mechanism, such as a switch, that controls whether wireless communication is available or operable. In particular, the control mechanism is used to prohibit operation of the antenna system during selected periods. Desirably, the control mechanism controls the ability of the antenna system to operate based upon the positioning of the retractable platform and by controlling the supply of electrical power to the antenna system.
The antenna system advantageously saves power and/or battery life by being turned off in the storage position. Additionally, by preventing use of the antenna or wireless system in the storage position, this may comply with future Federal Aviation Administration (FAA) or Federal Communication Commission (FCC) requirements that wireless communication not be permitted in certain locations or during specific times. For example, wireless communication may not be permitted on airplanes, in hospitals, at construction sites, within high security buildings, or at other sensitive or protected areas. Thus, by simply storing the retractable platform in the storage position, wireless communication is not permitted. The other features of the communication card and/or computer, however, may still be usable even though wireless communication is not possible. Thus, the user may continue to use the communication card and/or computer, even though wireless communication is not permitted.
Significantly, by storing the retractable platform in the retracted position, that physically and clearly indicates that wireless communication is not possible. Thus, a pilot or flight attendant, for example, could quickly and easily ensure that wireless communication is not possible, even though the computer or electronic device is still operable. Desirably, a visual indicator or other signal may also be used to confirm that the wireless communication feature is disabled.
Still another aspect of the antenna system is a mechanism for retracting the antenna into the storage position when wireless communication is not desired and deploying the antenna when wireless communication is desired. Desirably, the mechanism used to extend and retract the antenna is a retractable platform that is movable between an extended portion and a retracted position. The antenna is desirably attached to the outer portion of the retractable platform such that it is located a sufficient distance from the body of the computer in the extended position. This optimizes the reception of the antenna because the computer or communication card can block, shield or interfere with the wireless signal. Additionally, because wireless communication is not available when the retractable platform is in the storage position, the antenna is not transmitting signals or causing RF interference within the electronic device. This may help improve the performance of the electronic device.
Yet another aspect is an antenna system that is an integral part of a communication card. In particular, the communication card includes a retractable platform and at least an antenna is mounted to the platform. The circuitry or other components necessary for wireless communication are located in the communication card and/or the retractable platform. Advantageously, if the antenna system is an integral part of the communication card, the card can be quickly and easily connected to various suitable electronic devices, and the card can be used interchangeably with other devices. This increases the flexibility and potential uses of the antenna system and communication card. The antenna or antenna system can also be removably attached to the communication card or other suitable electronic device to allow different antennas to be attached and facilitate repair.
Another aspect is an antenna system that can be optimized for use with a particular wireless system. For example, the antenna can be configured to receive or transmit specifically on the frequencies of the desired wireless communication system.
Another aspect of the antenna system is an indicator that is attached to the retractable platform or communication card. The indicator is preferably a light source that indicates use of the antenna system or that wireless communication is available. The indicator can also indicate that the antenna system or wireless communication is not available or inoperable. The indicator may also be used to indicate other information such as power, status, diagnostics, etc.
Advantageously, because the antenna and its associated components are very small and compact, it has minimum size and space requirements. Accordingly, the antenna system can be easily attached to the retractable platform and/or communication card, and it requires only a small space. This significantly decreases design and manufacturing costs.
A preferred embodiment is an apparatus that controls the operational state of the antenna system based upon the positioning of the retractable platform. The antenna is attached to the retractable platform and the platform is selectively movable between an extended position and a retracted position. Wireless communication is enabled when the retractable platform is in the extended position, but wireless communication is not available in the retracted position. Desirably, a control mechanism is used to determine if wireless communication is available. For example, the control mechanism may only provide electrical power to the antenna system in the extended position and not the retracted position. The control mechanism, for example, may include a switch, optical sensor, or electrical contacts to control whether wireless communication is possible. Advantageously, because the antenna system may be selectively powered, this can greatly reduce the amount of electrical power used by the host device, which thereby increase its useful battery life. Significantly, while the antenna system cannot be used to transmit or receive wireless signals when the platform is retracted, the computer and/or communication card may still be used.
Another preferred embodiment is an antenna system mounted to a retractable platform that is moveable between an extended position and a retracted position. Extension of the retractable platform causes a control mechanism to indicate that the antenna system is xe2x80x9cready for use.xe2x80x9d This status will be supplied to an appropriate control circuit. For instance, the control circuit can supply electrical power to the antenna system to enable wireless communication. When the connector is retracted, the control mechanism indicates that the antenna system is xe2x80x9cinoperative or not usable.xe2x80x9d Accordingly, the control circuit could, for example, cut off or limit the electrical power that is supplied to the antenna system such that the antenna system could not be used for wireless communication.
These and other aspects, features and advantages of the present invention will become more fully apparent from the following detailed description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.